Abstract: A steel strand stress detection method based on LC oscillation and magneto-elastic theory was proposed，which only needed to detect the stress at two ends of the steel strand.The basic detection principle was introduced and LC oscillation method was designed.The corresponding experimental system was set up，and the prestressed steel strand was used for stress measurement experiment.Experiment results show that the vibration frequency of the LC oscillator increases with the increase of steel strand stress.Since the proposed method detects stress only at the unloaded place of steel strands，it is hopeful to be used in detecting the pre-stress structures in service.

Key words: bridge engineering, strand, prestress, LC oscillation, magneto elastic effect

摘要： 提出了一种在LC振荡作用下，利用磁弹效应原理，只需对钢绞线端部测量的钢绞线应力检测方法；介绍了测量基本原理，设计出了LC振荡方法，搭建了相应的实验系统，并用预应力钢绞线进行了应力测量实验。实验结果表明：随着钢绞线应力增加，LC振荡器振荡频率增加。由于只需在钢绞线的非受力位置加载测量，该方法有望用于在役结构预应力检测。

关键词: 桥梁工程, 钢绞线, 预应力, LC振荡, 磁弹效应